import tkinter as tk
import datetime
import time

root = tk.Tk()
root.geometry('500x300')


def btn_click():
    print('按钮被点击了')
    return None


# command 点击事件 需要复制一个函数对象
btn = tk.Button(root, text='确定', font=('宋体', 20), command=btn_click)
btn.pack()

root.mainloop()
